U.S. patent application number 14/977028 was filed with the patent office on 2017-06-22 for center plenum support for a multiwall turbine airfoil casting.
The applicant listed for this patent is General Electric Company. Invention is credited to Gregory Thomas Foster, Michelle Jessica Iduate, Brendon James Leary, David Wayne Weber, Joseph Anthony Weber.
Application Number | 20170173672 14/977028 |
Document ID | / |
Family ID | 57544254 |
Filed Date | 2017-06-22 |
United States Patent
Application |
20170173672 |
Kind Code |
A1 |
Foster; Gregory Thomas ; et
al. |
June 22, 2017 |
CENTER PLENUM SUPPORT FOR A MULTIWALL TURBINE AIRFOIL CASTING
Abstract
A core for a turbine airfoil casting according to an embodiment
includes: a center plenum section; and a plurality of outer passage
sections; wherein the center plenum section includes at least one
boss extending outwardly from the center plenum to an outer profile
of the core.
Inventors: |
Foster; Gregory Thomas;
(Greer, SC) ; Weber; David Wayne; (Simpsonville,
SC) ; Iduate; Michelle Jessica; (Simpsonville,
SC) ; Leary; Brendon James; (Simpsonville, SC)
; Weber; Joseph Anthony; (Simpsonville, SC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
General Electric Company |
Schenectady |
NY |
US |
|
|
Family ID: |
57544254 |
Appl. No.: |
14/977028 |
Filed: |
December 21, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B22C 9/24 20130101; F05D
2260/20 20130101; B22C 9/108 20130101; F01D 5/187 20130101; B22C
9/103 20130101; G01B 21/08 20130101; F05D 2220/32 20130101; F05D
2230/21 20130101; B22C 9/12 20130101; G01B 17/02 20130101; B22C
21/14 20130101 |
International
Class: |
B22C 9/10 20060101
B22C009/10; B22C 9/24 20060101 B22C009/24; G01B 17/02 20060101
G01B017/02; F01D 5/18 20060101 F01D005/18 |
Claims
1. A core for a turbine airfoil casting, comprising: a center
plenum section; and a plurality of outer passage sections; wherein
the center plenum section includes at least one boss extending
outwardly from the center plenum to an outer profile of the
core.
2. The core according to claim 1, wherein the at least one boss
includes a first boss extending outwardly from the center plenum
section toward a first side of the core, and a second boss
extending outwardly from the center plenum section toward a second
side of the core.
3. The core according to claim 2, wherein the first boss has an
outer contact surface having a contour matching a contour of a
corresponding contact area on a first setter block, and wherein the
second boss has an outer contact surface matching a contour of a
corresponding contact area on a second setter block.
4. The core according to claim 1, wherein the core is disposed
between a first setter block and a second setter block, and wherein
the at least one boss controls the position, and prevents movement
of, the center plenum section in a cavity formed by the lower
setter block and upper setter block during a firing process.
5. The core according to claim 1, wherein the at least one boss has
an elliptical shape.
6. The core according to claim 5, wherein the elliptical shape has
a length to width ratio in the range of about 3:1 to about
10:1.
7. The core according to claim 5, wherein the elliptical shape has
a length to width ratio of about 7:1.
8. The core according to claim 1, wherein the at least one boss
extends outwardly from the center plenum section between a pair of
the outer passage sections.
9. The core according to claim 1, wherein the at least one boss is
disposed on a pressure side or a suction side of the core.
10. The core according to claim 1, wherein the casting comprises a
multiwall airfoil casting.
11. A method for forming a core for a casting, comprising:
positioning a first side of a core on a first setter block, the
core comprising a center plenum section and a plurality of outer
passage sections, wherein the center plenum section includes at
least one boss extending outwardly from the center plenum to an
outer profile of the core; closing a second setter block against
the second side of the core; and heating the core.
12. The method according to claim 11, wherein the at least one boss
includes a first boss extending outwardly from the center plenum
section toward the first side of the core, and a second boss
extends outwardly from the center plenum section toward the second
side of the core.
13. The method according to claim 12, wherein the first boss has an
outer contact surface having a contour matching a contour of a
corresponding contact area on the first setter block, and wherein
the second boss has an outer contact surface matching a contour of
a corresponding contact area on the second setter block.
14. The method according to claim 12, wherein the first boss and
the second boss extend outwardly from the center plenum section to
an outer profile of the core.
15. The method according to claim 11, further comprising:
controlling, using the at least one boss, the position of the
center plenum sections in a cavity formed by the lower setter block
and upper setter block during the heating of the core.
16. The method according to claim 11, further comprising:
preventing, using the at least one boss, movement of the center
plenum sections in a cavity formed by the lower setter block and
upper setter block during the heating of the core.
17. The method according to claim 11, wherein the at least one boss
has an elliptical shape.
18. The method according to claim 17, wherein the elliptical shape
has a length to width ratio in the range of about 3:1 to about
10:1.
19. A method for measuring a thickness T.sub.1 of an inner wall of
a multiwall airfoil, the inner wall located between an outer
cooling passage and a central plenum of the multiwall airfoil, the
central plenum including a protrusion extending toward an outer
wall of the multiwall airfoil, the method comprising: obtaining a
thickness measurement T.sub.2 of an outer wall of the multiwall
airfoil at a first point adjacent the outer cooling passage; and
obtaining a thickness measurement T.sub.3 of the outer wall of the
multiwall airfoil at a second point adjacent the protrusion of the
central plenum; wherein the thickness T.sub.1 of the inner wall of
the multiwall airfoil is given by
T.sub.1=(T.sub.3+D.sub.1)-(T.sub.2+D.sub.2), wherein D.sub.1 is a
depth of the outer cooling passage and D.sub.2 is a depth of the
protrusion of the central plenum, and wherein D.sub.1 and D.sub.2
are known from corresponding dimensions of a core used to form the
multiwall airfoil.
20. The method according to claim 19, wherein the protrusion
corresponds to a lower boss or an upper boss of a central plenum
section of the core.
Description
BACKGROUND OF THE INVENTION
[0001] The disclosure relates generally to turbine systems, and
more particularly, to a center plenum support for a multiwall
turbine airfoil casting.
[0002] Traditional means for providing location and rib wall
thickness control for the center plenum of a multiwall or double
wall casting have been through the use of bumpers between the
center plenum and the outer cooling passages. Bumpers are a raised
pad on either the center plenum or cooling passages that limits the
gap between these two features. Ideally, the bumpers would not
touch, but occasionally they do, leaving a hole between the two
cavities in the casting process. The number of holes formed from
these connections is unknown, leading to uncertainty in the cooling
flow distribution in the part.
BRIEF DESCRIPTION OF THE INVENTION
[0003] A first aspect of the disclosure provides a core for a
turbine airfoil casting including: a center plenum section; and a
plurality of outer passage sections; wherein the center plenum
section includes at least one boss extending outwardly from the
center plenum to an outer profile of the core.
[0004] A second aspect of the disclosure provides a method for
forming a core for a casting, comprising: positioning a first side
of a core on a first setter block, the core comprising a center
plenum section and a plurality of outer passage sections, wherein
the center plenum section includes at least one boss extending
outwardly from the center plenum to an outer profile of the core;
closing a second setter block against the second side of the core;
and heating the core.
[0005] A third aspect of the disclosure provides method for
measuring a thickness T.sub.1 of an inner wall of a multiwall
airfoil, the inner wall located between an outer cooling passage
and a central plenum of the multiwall airfoil, the central plenum
including a protrusion extending toward an outer wall of the
multiwall airfoil, the method including: obtaining a thickness
measurement T.sub.2 of an outer wall of the multiwall airfoil at a
first point adjacent the outer cooling passage; and obtaining a
thickness measurement T.sub.3 of the outer wall of the multiwall
airfoil at a second point adjacent the protrusion of the central
plenum; wherein the thickness T.sub.1 of the inner wall of the
multiwall airfoil is given by
T.sub.1=(T.sub.3+D.sub.1)-(T.sub.2+D.sub.2), wherein D.sub.1 is a
depth of the outer cooling passage and D.sub.2 is a depth of the
protrusion of the central plenum, and wherein D.sub.1 and D.sub.2
are known from corresponding dimensions of a core used to form the
multiwall airfoil.
[0006] The illustrative aspects of the present disclosure solve the
problems herein described and/or other problems not discussed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] These and other features of this disclosure will be more
readily understood from the following detailed description of the
various aspects of the disclosure taken in conjunction with the
accompanying drawing that depicts various embodiments of the
disclosure.
[0008] FIG. 1 is a cross-sectional view of a core disposed between
upper and lower fire setter blocks, according to embodiments.
[0009] FIG. 2 depicts a cavity formed by the upper and lower fire
setter blocks of FIG. 1, according to embodiments.
[0010] FIG. 3 is a first cross-sectional view of a core, according
to embodiments.
[0011] FIG. 4 is a plan view of a lower boss and adjacent outer
passage sections of the core of FIG. 3, according to
embodiments.
[0012] FIG. 5 is a plan view of an upper boss and adjacent outer
passage sections of the core of FIG. 3, according to
embodiments.
[0013] FIG. 6 is a second cross-sectional view of the core,
according to embodiments.
[0014] FIG. 7 is a cross-sectional view of the core of FIG. 3,
disposed between upper and lower fire setter blocks, according to
embodiments.
[0015] FIG. 8 is a first cross-sectional view of a multiwall
airfoil formed using the core of FIGS. 3 and 6, according to
embodiments.
[0016] FIG. 9 is a second cross-sectional view of a multiwall
airfoil formed using the core of FIGS. 3 and 6, according to
embodiments.
[0017] FIGS. 10 and 11 are plan views of a portion of a multiwall
airfoil formed using the core of FIGS. 3 and 6, according to
embodiments.
[0018] FIG. 12 is a plan view of a core including multiple lower
bosses.
[0019] FIG. 13 is a plan view of a core including multiple upper
bosses.
[0020] It is noted that the drawing of the disclosure is not to
scale. The drawing is intended to depict only typical aspects of
the disclosure, and therefore should not be considered as limiting
the scope of the disclosure. In the drawing, like numbering
represents like elements between the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0021] As indicated above, the disclosure relates generally to
turbine systems, and more particularly, to a center plenum support
for a multiwall turbine airfoil casting.
[0022] A setter fire step is often employed to control and correct
the dimensions of a core (e.g., a ceramic core) used in the casting
process of a multiwall airfoil (e.g., a multiwall turbine airfoil).
As depicted in FIG. 1, this step involves, for example, positioning
the core 10 in a lower setter block 12, closing an upper setter
block 14 against the core 10 and the lower setter block 12, and
performing a firing process. The lower and upper setter blocks 12,
14 form a cavity 16 (FIG. 2) defining the desired shape of the core
10. During the firing process, the core 10 heats up and softens.
The weight of the upper setter block 14 against the softened core
10 conforms the core 10 to the shape of the cavity 16. As shown in
FIG. 2, the cavity 16 is defined by the inner surfaces 18, 20 of
the lower and upper setter blocks 12, 14.
[0023] The core 10 is used during the casting process of a
multiwall airfoil 22 (see, e.g., FIGS. 8 and 9). As depicted in
detail in FIG. 3, the core 10 includes a plurality of center plenum
sections 24, which are configured to form center plenums 124 (FIGS.
8-11) of the multiwall airfoil 22, and a plurality of outer passage
sections 26, which are configured to form outer cooling passages
126 (FIGS. 8-11) of the multiwall airfoil 22. The core 10 has an
outer surface 28 that is at least partially defined by the exterior
surfaces 30 of the outer passage sections 26.
[0024] According to embodiments, each center plenum section 24
includes a center section 32, at least one lower boss 34, and at
least one upper boss 36. The lower and upper bosses 34, 36 extend
outwardly from the center section 32 of the center plenum section
24 to, but not beyond, the outer surface 28 of the core 10. Each
lower boss 34 is located on a "pressure" or concave side of the
core 10, corresponding to the pressure side of a multiwall airfoil
22 (FIGS. 8, 9) formed using the core 10. Similarly, each upper
boss 36 is located on the "suction" or convex side of the core 10,
corresponding to a suction side of a multiwall airfoil 22 (FIGS. 8,
9) formed using the core 10. The lower and upper bosses 34, 36 are
configured to control the position, and prevent the movement of,
the center plenum sections 24 in the cavity 16 formed by the lower
setter block 12 and upper setter block 14 during firing. As shown
in FIGS. 3-5 and 7, each lower and upper boss 34, 36 may extend
outwardly from the center plenum section 24 between a pair of the
outer passage sections 26.
[0025] The lower and upper bosses 34, 36 are configured to be
securely engaged by the inner surfaces 18, 20 of the lower and
upper setter blocks 12, 14. To provide a secure engagement, as
shown in FIG. 7, an outer contact surface 38 of each lower boss 34
has a contour that matches the contour of the inner surface 18 of
the lower setter block 12 at the corresponding contact area.
Similarly, the outer contact surface 40 of each upper boss 36 has a
contour that matches the contour of the inner surface 20 of the
upper setter block 14 at the corresponding contact area.
Advantageously, unlike the related art, the lower bosses 34 and
upper bosses 36 do not contact the outer passage sections 26,
thereby preventing the formation of holes between the center
plenums 124 and outer cooling passages 126 (FIGS. 8-11) of a
multiwall airfoil 22 formed using the core 10.
[0026] A plan view of a lower boss 34 and adjacent outer passage
sections 26 is depicted in FIG. 4. A plan view of an upper boss 36
and adjacent outer passage sections 26 is depicted in FIG. 5.
[0027] As shown in FIG. 4, each lower boss 34 may have a
substantially elliptical configuration. A channel 42 (see also
FIGS. 3 and 7 (in phantom) and FIG. 6) diverges around a first end
of the lower boss 34 and converges at a second end of the lower
boss 34. To limit turbulence and pressure loss of air (represented
by arrows A in FIG. 10) flowing through outer cooling passages 126
corresponding to the outer passage sections 26 of the core 10 on
either side of the lower boss 34, the lower boss 34 may have a
length to width ratio of about 3:1 to about 10:1. In a particular
embodiment, a length to width ratio of about 7:1 may be used.
Although described as elliptical, the lower boss 34 may have any
other suitable configuration.
[0028] Similarly, as shown in FIG. 5, in embodiments, the upper
boss 36 may also have a substantially elliptical configuration. A
channel 44 (see also FIGS. 3 and 7 (in phantom) and FIG. 6)
diverges around a first end of the upper boss 36 and converges at a
second end of the upper boss 36. To limit turbulence and pressure
loss of air (represented by arrow B in FIG. 11) flowing through
outer cooling passages 126 corresponding to the outer passage
sections 26 of the core 10 on either side of the upper boss 36, the
upper boss 36 may have a length to width ratio of about 3:1 to
about 10:1. In a particular embodiment, a ratio of about 7:1 may be
used. Although described as elliptical, the upper boss 36 may have
any other suitable configuration.
[0029] FIG. 12 is a plan view of the core 10 including multiple
lower upper bosses 34. FIG. 13 is a plan view depicting the core 10
including multiple upper bosses 36. As depicted in FIG. 12, a
channel 42 diverges around a first end of each lower boss 34 and
converges at a second end of each lower boss 34. The channel 42
also connects a lower boss 34 to an adjacent lower boss 34.
Similarly, as depicted in FIG. 13, a channel 44 diverges around a
first end of each upper boss 36 and converges at a second end of
each upper boss 36. The channel 44 also connects an upper boss 34
to an adjacent upper boss 34.
[0030] According to embodiments, the center plenum sections 24
provide positional control without the use of the bumpers,
eliminating holes formed from the use of bumpers that potentially
allow cooling flow to communicate between cavities (e.g., between
the center plenums 124 and outer cooling passages 126 (FIGS.
8-11)). Further, better control of the position of the center
plenum sections 24 results in a more tightly controlled rib wall
thickness without the use of the bumpers, allowing the turbine
blade to use less cooling air in a more deterministic solution,
thus increasing the performance and output of the gas turbine. A
direct line of contact of the lower and upper bosses 34, 36 of the
center plenum sections 24 to the inner surfaces 18, 20 of the lower
and upper setter blocks 12, 14 is created allowing the position of
the central plenum sections 24 to be controlled independently of
the outer cooling sections 26.
[0031] It has been difficult and expensive to measure the thickness
of an inner wall of a multiwall airfoil, often requiring MRI
measurements. Such an inner wall 130 is depicted in FIG. 8.
[0032] According to embodiments, the thickness T.sub.1 of the inner
wall 130 of the multiwall airfoil 22 can be readily inferred,
without requiring expensive and time consuming MRI measurements.
For example, an outer wall 132 of the multiwall airfoil 22 can be
measured (e.g., ultrasonically) at first and second points X, Y to
determined thicknesses T.sub.2 and T.sub.3, respectively. Point X
is adjacent an outer cooling passage 126, while point Y is adjacent
a protrusion 134 of a center plenum 124 formed by (in this case) a
lower boss 34 of a central plenum section 24 of the core 10 (FIG.
7). Since the depth D.sub.1 of the outer cooling passage 126 and
the depth D.sub.2 of the protrusion 134 of the center plenum 124
are known from the dimensions of the corresponding outer passage
section 26 and corresponding lower boss 34, respectively, of the
core 10, the thickness T.sub.1 of the inner wall 130 can be
determined as: T.sub.1=(T.sub.3+D.sub.2)-(T.sub.2+D.sub.1). The
thickness of the inner wall 130 may be determined in a similar
manner at other points of the multiwall airfoil 22.
[0033] In various embodiments, components described as being
"coupled" to one another can be joined along one or more
interfaces. In some embodiments, these interfaces can include
junctions between distinct components, and in other cases, these
interfaces can include a solidly and/or integrally formed
interconnection. That is, in some cases, components that are
"coupled" to one another can be simultaneously formed to define a
single continuous member. However, in other embodiments, these
coupled components can be formed as separate members and be
subsequently joined through known processes (e.g., fastening,
ultrasonic welding, bonding).
[0034] When an element or layer is referred to as being "on",
"engaged to", "connected to" or "coupled to" another element, it
may be directly on, engaged, connected or coupled to the other
element, or intervening elements may be present. In contrast, when
an element is referred to as being "directly on," "directly engaged
to", "directly connected to" or "directly coupled to" another
element, there may be no intervening elements or layers present.
Other words used to describe the relationship between elements
should be interpreted in a like fashion (e.g., "between" versus
"directly between," "adjacent" versus "directly adjacent," etc.).
As used herein, the term "and/or" includes any and all combinations
of one or more of the associated listed items.
[0035] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the disclosure. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof.
[0036] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is defined by the
claims, and may include other examples that occur to those skilled
in the art. Such other examples are intended to be within the scope
of the claims if they have structural elements that do not differ
from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal languages of the claims.
* * * * *